Сокротить дроби , и затем к их общему знаменателю 25/45и14/35; 12/144и2/36; 32/44и9/33; 2/50и3/105; 75/200и35/90; 12/48и3/18; 80/180и20/225; 12/60и5/35
5/9 и 2/5, 25/45 и 18/45; 1/12 и 1/18, 3/36 и 2/36; 8/11 и 3/11; 1/25 и 1/35, 3/75 и 5/75; 3/8 и 7/18, 27/72 и 28/72; 1/4 и 1/6, 3/12 и 2/12; 4/9 и 4/45, 20/45 и 4/45; 1/5 и 1/7, 7/35 и 5/35.